<p> REDOX REACTIONS</p><p>OXIDATION  The LOSS of electrons.  An increase of the oxidation number.  Group one and two metals oxidize spontaneously.  Transition metals are oxidized by metals below them on table J.  Active non-metals can only be oxidized by an industrial process called electrolysis.  All oxidations must balance for MASS and CHARGE, in this case there is one Ca on each side. Use the algebra bubble (wiener) to balance charge.  ALWAYS add electrons to the more positive side of the oxidation to balance charge.</p><p>Metals in the Oxidation state Metals in the 0.0 ionic oxidation increases from 0 to 2+ oxidation state are states are therefore it is solids. aqueous.. oxidation.</p><p>Electrons 0 2+ - on RIGHT Ca (s)  Ca (aq) + 2e in oxidation.. 0 = 2 + 2(- 1) Charge of calcium ion, Charge of an electron is -1, group 2 are therefore two of them are 2+ always. added to cancel the 2+ of Ca to 0.</p><p>REDUCTION  The GAIN of electrons.  A decrease (reduction) of the oxidation number.  Halogens reduce spontaneously.  Transition metals are reduced by metals above them on table J.  Active metals can only be reduced by an industrial process called electrolysis.  All reductions must balance for MASS and CHARGE, on each side. Use the algebra bubble (wiener) to balance charge.  ALWAYS add electrons to the more positive side of the reduction to balance charge.</p><p>Oxidation state Cl in the 0.0 decreases from 0 to 1- Electrons on the oxidation state is therefore it is left in reduction a gas. reduction.</p><p>0 - - Cl2 (g) + 2e  2 Cl 2(0) + 2(-1) = 2(-1) Oxidation state of each Cl is 0, HONClBrIF</p><p>You need 2 electrons to make the left -2, ad to the o state if the Cl 2. Charge of a halogen . ion is usually 1- when it is free in solution.</p>